Explanation

(b)
(i)${CH}_{3} - CH = CH - {CH}_{3}\underset{\frac{Zn}{H_{2}O}}{\overset{{\ \ \ \ \ \ \ O}_{3}\ \ \ \ \ \ }{\rightarrow}}$
$CH_{3}CHO + CH_{3}CHO + ZnO$
2 molecules of ethanal
(ii)$C_{6}H_{5}CH = {CH}_{2}\underset{\frac{Zn}{H_{2}O}}{\overset{{\ \ \ \ \ \ \ O}_{3}\ \ \ \ \ \ }{\rightarrow}}$
$C_{6}H_{5}CHO + HCHO + ZnO$
benzaldehyde methanol
(iii)${CH}_{3}CH = {CH}_{2}\underset{\frac{Zn}{H_{2}O}}{\overset{{\ \ \ \ \ \ \ O}_{3}\ \ \ \ \ \ }{\rightarrow}}CH_{3}CHO + HCHO$
Ethanol methanol
(iv)${{(CH}_{3})}_{2}C = C\left( {CH}_{3} \right)_{2}\underset{\frac{Zn}{H_{2}O}}{\overset{{\ \ \ \ \ \ \ O}_{3}\ \ \ \ \ \ }{\rightarrow}}$
${CH}_{3}{COCH}_{3} + {CH}_{3}{COCH}_{3} + ZnO$
2 molecules of acetone